Exploring, drilling and completing hydrocarbon and other wells are generally complicated, time consuming, and ultimately very expensive endeavors. As a result, over the years, a significant amount of added emphasis has been placed on overall well architecture, monitoring and follow on interventional maintenance. Indeed, perhaps even more emphasis has been directed at minimizing costs associated with applications in furtherance of well formation, monitoring and maintenance. All in all, careful attention to the cost effective and reliable execution of such applications may help maximize production and extend well life. Thus, a substantial return on the investment in the completed well may be better ensured.
Depending on the nature and architecture of the well, interventional maintenance may be a routine part of operations. For example, proper well management may require the periodic clean-out of debris or scale from certain downhole locations. This may require isolating the location at issue and halting production during the clean out. Indeed, such isolating may be required in the natural course of completions, for example, to allow for perforating and/or stimulating applications to proceed. That is, in certain instances, high pressure perforating and stimulating of well regions may be called for. In this case, the active perforating or stimulating intervention may be preceded by the added intervention of closing off and isolating the well regions with mechanisms capable of accommodating such high pressure applications.
Closing off of a well region for a subsequent high pressure application may be achieved by way of setting a mechanical plug. That is, a plug may be positioned at a downhole location and ‘set’ to seal off a downhole region adjacent thereto. The plug is configured to accommodate the high pressures associated with perforating or stimulating as noted. Thus, it is generally radially expandable in nature through the application of substantial compressible force. In this manner, slips of the radially expandable plug may be driven into engagement with a casing wall of the well so as to ensure its sufficient anchoring. By the same token, the radial responsiveness of elastomeric portions of the plug may help ensure adequate sealing for the high pressure application to be undertaken.
Unfortunately, the noted compression and overall setting application is generally achieved by way of an explosively powered setting tool that is coupled to the plug. Even setting aside the transport hazards and limited reliability associated with such explosively driven applications, the operator is unable to direct a controlled, monitored, or intelligent setting application when such is explosively driven. Thus, the setting application generally proceeds in an unintelligent manner without readily available data to ensure its effectiveness.
Alternatively, in the case of perforating or stimulating applications, electronics may be used to trigger the application. However, such electronics are relatively unsophisticated and limited to initiating a trigger, for example, for perforating. Thus, the cost of replacement due to heat or shock damage encountered in carrying out the application may be relatively low. To the contrary, substituting explosives with electronics for a setting application involves directing a motor drive unit over the period of the application (e.g. as opposed to merely initiating a perforating trigger). As such, the electronics involved may utilize digital signal processing and other sophisticated capacity, thereby driving up replacement cost where heat and/or shock damage are experienced over the course of the application.
Unfortunately, techniques for mitigating heat and shock damage to sophisticated electronics packaging generally run contrary to one another. In the particular circumstance of plug setting, the setting tool, packaging, and plug may be exposed to about 200 g's or more, not to mention temperatures in excess of 150° C. So, for example, if heat dissipation is addressed through a conventional technique including a heat sink in conjunction with spring compression directed at the electronics, secondary shocks in excess of 200 g's are likely imparted on the electronics. In other words, the heat dissipation technique may have amplified shock directed at the electronics.
Alternatively, where electronics are tightly accommodated through a conventional o-ring or centralizer mounting technique to enhance shock tolerance, thermal contact between the electronics and heat sink, or other thermal dissipating structure, is compromised. Ultimately, due to such counterintuitive options available for dealing with heat and shock, explosively driven setting is generally utilized in lieu of superior, but costly electronics that would allow for a controlled, monitored, and/or intelligent setting application.